1. Field of the Invention
The present invention relates to the encoding and decoding of digital video image frames, and particularly to the coding of pixel color values.
2. Description of the Related Art
A well known technique is run length coding, used for example as one of the coding modes in the Compact Disc interactive (CD-i) standard. The technique allows sets of adjacent pixel values to be coded more compactly by specifying the color once and then the count of the number (n) of identical pixels instead of repeating the color code (n) times. Further information about run length coding may be found in, for example, "Principles of Interactive Computer Graphics" by W M Newman and R F Sproul, International Student Edition, 1979, pp 287-289, pub McGraw-Hill, ISBN 0-07-066455-2, and a brief summary of the relevant points will be given below with reference to prior art FIGS. 1 to 3 of the accompanying drawings.